The present invention relates to steganographic decoding systems, and more particularly relates to such systems whose steganographic decoding operations can be changed, such as with the passage of time, or with the occurrence of an event.
In accordance with certain embodiments disclosed herein, multi-bit auxiliary information is hidden in audio and imagery (e.g., digital photographs, video), using steganographic techniques. Such information can be used for various purposes, including identifying audio/imagery as originating from a particular source, copy control, etc. In some embodiments, operation of the system changes over time. This change may be triggered by various events, including passage of new information to the system through audio or imagery being processed.